Civil Engineering - Soil Mechanics and Foundation Engineering MCQs Part 5

1. Soils containing organic matters

A.
are of spongy nature

B.
swell with decrease of moisture

C.
shrink with increase of moisture content

D.
none of these.

 Answer Option A

2. A soil not fully consolidated under the existing over-burden pressure, is called

A.
pre-consolidated

B.
normally consolidated

C.
under-consolidated

D.
none of these.

 Answer Option C

3. The angle of internal friction is maximum for

A.
angular-grained loose sand

B.
angular-grained dense sand

C.
round-grained dense sand

D.
round-grained loose sand

E.
clays.

 Answer Option B

4. If G is specific gravity of sand particles, e is porosity, the critically hydraulic gradient

A.
ic =

B.
ic =

C.
ic =

D.
ic =

 Answer Option C

5. A grillage foundation

A.
is provided for heavily loaded isolated columns

B.
is treated as spread foundation

C.
consists of two sets of perpendicularly placed steel beams

D.
all the above.

 Answer Option D

6. The plasticity of fine soils may be assessed by means of

A. dry strength test

B. toughness test

C. dilatancy test

D. all of these.

 Answer Option D

7. The density of soil can be increased

A. by reducing the space occupied by air

B. by elastic compression of soil grains

C. by expelling water from pores

D. All the above.

 Answer Option D

8. The length/diameter ratio of cylindrical specimens used in triaxial test, is generally

A. 1

B. 1.5

C. 2

D. 2.5

E. 3

 Answer Option C

9. Pick up the correct statement from the following:

A. The object of classifying soils is to arrange them into groups according to their properties and behaviour

B. A soil classification system is meant to provide an accepted and systematic method of describing the various types of soils eliminating personal factors

C. The first category of soil classification is based on grain size of the soil

D. The second category of soil classification is based on fine as well as coarse grains

E. All the above.

 Answer Option E

10. A suspended particle falls through a height H cm in water in t minutes. If the viscosity of water is η and specific gravity of the particle is G, the diameter of the particle is (where M is a constant factor)

A. 103M

B. 104M

C. 105M

D. 102M

 Answer Option C

11. Laplacian fundamental equation for a non-compressible flow in three dimensions, is

A.

B.

C.

D. none of these.

 Answer Option C

12. The bearing capacity of a soil depends upon

A. size of the particles

B. shape of the particles

C. cohesive properties of particles

D. internal frictional resistance of particles

E. all the above.

 Answer Option E

13. A direct shear test possesses the following disadvantage:

A. A relatively thin thickness of sample permits quick drainage

B. A relatively thin thickness of sample permits quick dissipation of pore pressure developed during the test

C. As the test progresses the area under shear, gradually changes

D. none of these.

 Answer Option C

14. Through a point in a loaded soil mass, there exists n typical planes mutually orthogonal on which the stress is wholly normal and no shear stress acts, if n is

A. 1

B. 2

C. 3

D. 4

 Answer Option C

15. The pressure that builds up in pore water due to load increment on the soil, is termed

A. excess pore pressure

B. excess hydrostatic pressure

C. hydrodynamic pressure

D. all the above.

 Answer Option D

16. The ratio of emax and emin of silty sand, is

A. 2.0

B. 5

C. 3.0

D. 3.5

E. 4.0

 Answer Option C

17. A flow net may be utilised for the determination of

A. exit gradient

B. seepage

C. hydrostatic pressure

D. seepage pressure

E. all the above.

 Answer Option E

18. The neutral stress in a soil mass is

A. force per neutral area

B. force per effective area

C. stess taken up by the pore water

D. stress taken up by solid particles.

 Answer Option C

19. If voids ratio is 0.67, water content is 0.188 and specific gravity is 2.68, the degree of saturation of the soil, is

A. 25%

B. 40%

C. 60%

D. 75%

 Answer Option D

20. If water content of a soil is 40%, G is 2.70 and void ratio is 1.35, the degree of saturation is

A. 70%

B. 75%

C. 80%

D. 85%

E. 90%

 Answer Option C

21. If β is the surcharge angle of a backfill with an angle of internal friction φ, the coefficient of active earth pressure given by Rankine's theory, is :

A.

B.

C.

D. none of these.

 Answer Option B

22. A structure is erected on an impervious clay whose thickness is 12 m. Drainage is possible both at upper and lower surfaces. Coefficient of consolidation is 0.015 cm2 per minute. For attaining 50% consolidation with a time factor 0.20, the number of days required

A. 3233

B. 3123

C. 33331

D. 3313

 Answer Option C

23. Which one of the following statements is true for Mohr-Coulomb envelope ?

A. Coulomb suggests that the relationship between shear strength and normal stress, is adequately represented by the straight line

B. The generalised Mohr theory suggests that, though the shear stress depends on the normal stress, the relation is not linear

C. Coulomb and Mohr suggest that a definite relationship exists among the principal stress and the angle of internal friction

D. For an ideal pure friction material, the straight line passes through the origin.

E. All the above.

 Answer Option E

24. The intensity of active earth pressure at a depth of 10 metres in dry cohesionless sand with an angle of internal friction of 30° and with a weight of 1.8 t/m3, is

A. 4 t/m2

B. 5 t/m2

C. 6 t/m2

D. 7 t/m2

E. 8 t/m2

 Answer Option C

25. On wetting, cohesive soils,

A. loose permeability

B. gain shear strength

C. loose elasticity

D. decrease their shear strength.

 Answer Option D

26. Pick up the correct statement from the following:

A. The range of water content between the liquid limit and plastic limit, is called plasticity index.

B. The ratio of the liquid limit minus the natural water content to the plasticity index of soils, is called consistency index

C. The ratio of natural water content minus its plastic limit to its plasticity index is called liquidity index

D. The ratio between plasticity index and flow index (i.e. slope of flow curve in case of liquid limit), is called toughness index

E. All the above.

 Answer Option E

27. 'Talus' is the soil transported by

A. wind

B. water

C. glacier

D. gravitational force.

 Answer Option D

28. A triaxial shear test is prefered to direct shear test, because

A. it can be performed under all three driange conditions with complete control

B. precise measurement of pore pressure and change in volume during test, is not posible

C. stress distribution on the failure plane, is non uniform

D. none of these.

 Answer Option A

29. Pick up the correct statement from the following:

A. When stress decreases, void, ratio decreases

B. When stress decreases, coefficient of permeability decreases

C. When stress decreases, coefficient of volume change decreases

D. When stress decreases void ratio, co-effi-cients of per-meability and volume change decrease.

 Answer Option D

30. Chemical weathering of soil is caused due to

A. oxidation

B. carbonation

C. hydration

D. leaching

E. all the above.

 Answer Option E

31. The Mohr's straight theory is based on the following fact :

A. Material fails essentially by shear

B. Ultimate strength of the material is determined by the stress in the plane of slip

C. Failure criterion is independent of the intermediate principal stress

D. All the above.

 Answer Option D

32. Hydrometer readings are corrected for:

A. temperature correction

B. meniscus correction

C. dispersing agent correction

D. meniscus and dispersing agent corrections

E. temperature, meniscus and dispersing agent corrections.

 Answer Option E

33. Tergazhi's theory of one dimensional consolidation assumes

A. soil is homogeneous and fully saturated

B. water and soil particles are incompressible

C. deformation of the soil, is entirely due to change in volume

D. Darcey's law for the velocity of flow of water through soil, is perfectly valid

E. all the above.

 Answer Option E

34. An unsaturated 100 cm3 sample of soil weighs 190 g. If its dried weight is 160 g, water content of the soil, is

A. 0.188

B. 0.288

C. 0.388

D. 0.488

E. 0.588

 Answer Option A

35. If the natural moisture content, the liquid limit and plastic limit of a soil sample are stated as 30.5%, 42.5% and 22.5% respectively, the ratio of liquidity index and plastic index, is

A.

B.

C. 2

D.

 Answer Option C

36. The specific gravity of Calcite is

A. 2.65

B. 2.72

C. 2.85

D. 2.90

 Answer Option B

37. The ratio of volume of air voids to the volume of total voids, is known as

A. air content

B. percentage air voids

C. percentage voids

D. porosity.

 Answer Option A

38. A plane inclined at an angle φ to the horizontal at which the soil is expected to stay in the absence of any lateral support, is known as

A. natural slope line

B. repose line

C. the φ line

D. all the above.

 Answer Option D

39. Tergazhi's theory of one dimensional consolidation assumes

A. load is applied in one direction

B. coefficient of permeability is constant

C. excess pore water drains out only in the vertical direction

D. time lag in consolidation is due entirely to permeability

E. all the above.

 Answer Option E

40. Pick up the correct statement from the following:

A. The dry density reduces by addition of water after attaining optimum moisture content

B. The line joining the peak of three moisture content graphs obtained by using three compactive energies, is called line of optimus

C. Well graded coarse grained soils can be compacted to a very high density as compared to fine grained soils

D. All the above. .

 Answer Option D

41. A soil mass is said to be in plastic equilibrium if

A. it is stressed to maximum

B. it is on the verge of failure

C. it is in plastic stage

D. it starts flowing.

 Answer Option B

42. Pick up the correct statement from the following:

A. The permeability of the coarse-grained soils may be reduced by grouting.

B. The process of injecting fluids (i.e. grouts) into the pores space of the soil, is called grouting.

C. The grouting increases the soil strength.

D. All the above.

 Answer Option D

43. A soil sample of mass specific gravity 1.92, has a moisture content 30%. If the specific gravity of solids is 2.75, the void ratio, is

A. 0.858

B. 0.860

C. 0.862

D. 0.864

 Answer Option C

44. The ratio of the weight of water to the weight of solids in a given mass of soil, is known

A. porosity

B. specific gravity

C. void ratio

D. water content.

 Answer Option D

45. During seepage through a soil, direction of seepage is always

A. parallel to equipotential lines

B. perpendicular to stream lines

C. perpendicular to equipotential lines

D. none of these.

 Answer Option C

46. The slip at critical angle, is generally known

A. δ 1-line

B. rupture plane

C. slip plane

D. all the above.

 Answer Option D

47. The property of a soil which allows it to be deformed rapidly without rupture, elastic rebound and also a volume change, is known

A. porosity

B. plasticity

C. permeability

D. ductility.

 Answer Option B

48. According to Rankine's fromula, the minimum depth of foundation

A.

B.

C.

D.

 Answer Option A